• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Fuel Economy

J

jediem

NAXJA Forum User
Location
PA
What great forum you have here=several replies to my earllier queastion in less than 24 hrs. At the risk of being a pia i"ll ask my second burning question about my 96'ZJ

I've just recently read on this forum about people getting 20+ mpg from their 4.0 l Cherokees. How do you do it?

I've done a complete tune up and Seafoam treatment+installed an Airaid cold air intake and throttle body spacer and my mileage remains the same 15 mpg combined city/hwy if I take it real easy. I plan on installing a more free flowing exhaust in the Spring. Is there anything else I should check that might be having a negaative effect on my fuel mileage?
 
Me007gold said:
what type of driving do you do most of the time?
Click to expand...
x2. I got a scangauge last week (tells you're instantaneous mpg and average for a trip). It's all about how you accelerate, and if highway, the speed you travel at. When I floor it, i get ~2mpg. Moderate accel is 8mpg and light accel is 11-12mpg (but takes longer so go figure). If on the highway, try to hang out behind a truck, not too close to get them mad but they'll make a huge difference. Just a tune up and careful driving you'll be getting ~20ish highway. I was getting 17-18 combined before with aggresive driving but with slower on highway and still slightly aggressive in city i get 19-20 combined (22 ave on highway at 60mph)
 
Lets not forget that E-10 has less energy per unit compared to gasoline. When I can, I got to a gas station that sells only gas, no E-10 crap. I hate E-10, it kills the economy in my jeep. So if your using E-10 and getting worse mileage, don't be surprised.
 
If your looking for a 4x4 with great mileage, invest in a Suzuki Samurai. The one I got has a 1.3 4 cylinder. Even with a double reduction case and toyota 8inch axels, 4.56 gears 6" lift and 36" tires, in 1:1 2wd, it gets a very nice 26ish MPG highway and 18 city. The small wheel base suits it well when in tight spots offroad. I'm not all about the imports, but you can't deny how good they are on a trail.
 
Don't know how old the oxygen sensor is since I bought the car with 95,000 mi on it last year, I was thinking that might be the next thing to replace. Tailpipe is black like it is running rich. It is all stock with original size tires and I do drive if very easily for max mileage, slow acceleration, no hard braking etc. My city driving is really country driving 40-50 mph max not constant stop and go and highway 15-20 miles at a shot at 60-65 mph so I don't get run over. And I too avoid the Ethanol cocktail when possible.
 
arent 96zj's running a NP249? or something along those lines. With the viscous coupler, All time all wheel drive.

New O2 sensor will help a lot, if it has gone bad and fuel sys. is running rich "open loop"
 
The O2 Sensor is the one that taps into the exhaust pipe just in front of the muffler?? My exhaust has also started to turn quite black, I am looking at having to replace the CPS due to intermittent shut-down problems, but it sounds like I might have to replace the O2 sensor also.

1995 Jeep XJ, 4.0HO, NP242, Auto, RHD, 130,000miles
 
Last edited:
Guys with standard trannys will get better mileage too. I;ve never seen over 20 in my autos, but regularly saw over 20 when I had a standard.
 
BillBraski said:
Lets not forget that E-10 has less energy per unit compared to gasoline. When I can, I got to a gas station that sells only gas, no E-10 crap. I hate E-10, it kills the economy in my jeep. So if your using E-10 and getting worse mileage, don't be surprised.
Click to expand...
I'm using E10 in my jeep and averaged 22.2mpg last highway trip. Not bad if you ask me.
 
outlander said:
how much are one of those scangauges?Will it work on the renix?
Click to expand...
Will not work with RENIX. Pre-OBD. The only thing we have to plug into is on passenger side under hood. I've read about 5-90 trying/wanting to decode data stream.

Returning hijacked thread to original topic

jediem: all you can do is make all efficency checks possible: tire pressure, excess weight, engine efficiencies, aerodynamics (roofracks), and change all fluids to syn (except transmission)
 
Last edited:
BillBraski said:
If your looking for a 4x4 with great mileage, invest in a Suzuki Samurai. The one I got has a 1.3 4 cylinder. Even with a double reduction case and toyota 8inch axels, 4.56 gears 6" lift and 36" tires, in 1:1 2wd, it gets a very nice 26ish MPG highway and 18 city. The small wheel base suits it well when in tight spots offroad. I'm not all about the imports, but you can't deny how good they are on a trail.
Click to expand...

My dad bought a Samurai new in 86 or 88 I don't remember. It stayed stock until my brother started driving it 10 years later. My dad got almost 40 mpg in it, my brother, 12 or 13. Its all in how you drive it.
 
Harlee&Tahoe said:
arent 96zj's running a NP249? or something along those lines. With the viscous coupler, All time all wheel drive.

New O2 sensor will help a lot, if it has gone bad and fuel sys. is running rich "open loop"
Click to expand...

I think that is only with the V8s or as an option isn't it
 
My 96 XJ country also gets crap mileage- but to confuse things it has a 98 4.0-Great tire-smoking power...but full size truck mileage...I'm down to either the classic cracked manifold screwing with the O2 sensor...or something weird with the newer motor and the older ECM and sensors...kind of have to wonder about the front axle being engaged to the driveshaft at all times, too...it seems like I picked up about 1mpg when I went with synthetic diff lube (Royal Purple) front and rear...
 
You must log in or register to reply here.

Similar threads

D
Troubleshoot my troubleshooting RE:poor fuel mileage
Replies
9
Views
1K
Hypoid
Hypoid
anthrax323
Chasing fuel economy? Lose some lift
Replies
3
Views
626
JohnX
JohnX
9
My '96 XJ Maintenance and MPG thread
2 3 4
Replies
74
Views
12K
96Sportxj
9
B
Fuel Economy - 1990 Renix XJ
2
Replies
22
Views
2K
SuperRA
S
M
Fuel economy
2
Replies
25
Views
2K
CharlesS
CharlesS
Back
Top